I hope you have already gotten help from a tutor at Uni. They seemed to have deliberately picked challenging options.
The walls of the blood vessel circled blue seem too thick to be a vein and yet it doesn’t quite look like an artery. The blood vessel circled yellow does have the thin walled appearance of a vein, so if I were in an exam and had to pick an option, I would pick the one circled yellow, but I wouldn’t be confident it was the answer they are looking for. Histopathology is NOT my area of expertise. If you still need help (it’s been a while since I checked in to this forum) I could send the images to one of my friends who has the expertise.